The Spiker is used by volleyball coaches throughout the world to develop and refine the skills of spiking and serving. This unique motivational aid has proven invaluable in teaching beginning players proper arm swing, extension, approach, and jump techniques, while affording more advanced players an opportunity to concentrate on perfecting existing skills. Strong aluminum pole telescopes from 6' to 12'. Durable ethafoam ball holder. Includes polyethylene base (fill with sand). Base provides stability and will not harm floor.